Wireless energy transfer with frequency hopping

• US 8,692,410 B2
• Filed: 12/31/2009
• Issued: 04/08/2014
• Est. Priority Date: 09/27/2008
• Status: Active Grant

• Current Assignee: WiTricity Corporation
• Original Assignee: WiTricity Corporation
• Inventors: Schatz, David A., Karalis, Aristeidis, Hall, Katherine L., Kesler, Morris P., Soljacic, Marin, Giler, Eric R., Kurs, Andre B., Kulikowski, Konrad J.
• Primary Examiner(s): KAPLAN, HAL IRA
• Application Number:
  US12/651,005
• Publication Number:
  US 20100171368A1
• Time in Patent Office: 1,559 Days
• Field of Search: 307/104
• US Class Current: 307/104
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: B60L 53/122 Circuits or methods for driving the primary coil, e.g. supplying electric power to the coil
• CPC Class Codes: B60L 53/124 Detection or removal of foreign bodies
• CPC Class Codes: B60L 53/126 Methods for pairing a vehicle and a charging station, e.g. establishing a one-to-one relation between a wireless power transmitter and a wireless power receiver
• CPC Class Codes: H01Q 1/248 provided with an AC/DC converting device, e.g. rectennas
• CPC Class Codes: H01Q 7/005 with variable reactance for tuning the antenna
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/00714 in response to battery charging or discharging current
• CPC Class Codes: H02J 7/007182 in response to battery voltage
• CPC Class Codes: H02J 7/04 Regulation of charging current or voltage
• CPC Class Codes: H03H 7/40 Automatic matching of load impedance to source impedance
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 : Plug-in electric vehicles

Abstract

Described herein are improved capabilities for a source resonator having a Q-factor Q₁>100 and a characteristic size x₁ coupled to an energy source, and a second resonator having a Q-factor Q₂>100 and a characteristic size x₂ coupled to an energy drain located a distance D from the source resonator, where the source resonator and the second resonator are coupled to exchange energy wirelessly among the source resonator and the second resonator.

Claims

1. A wireless energy transfer system comprising:

a source, having at least one source magnetic resonator, each resonator having a resonant frequency;

at least one power and control circuit, coupled to a power source, and configured to energize at least one source magnetic resonator to generate an oscillating magnetic field;

a device, having at least one device magnetic resonator configured to capture said oscillating magnetic field, each device magnetic resonator having a resonant frequency;

wherein magnetic energy transferred by the source to the device is converted into electrical energy by one or more device resonators;

wherein frequency of said oscillating magnetic field of said source is varied in time in a predetermined sequence; and

wherein the resonant frequency of at least one device magnetic resonator is varied in the same said predetermined sequence as the said oscillating magnetic field.

2. The system of claim 1, wherein the frequency of said oscillating magnetic field is varied to prevent power transfer to unauthorized devices.

3. The system of claim 1, wherein the frequency of said oscillating magnetic field is varied in time to a random value within a predetermined frequency range.

4. The system of claim 1, wherein the frequency of said oscillating magnetic field is varied between a set of discrete frequencies.

5. The system of claim 1, wherein the frequency of said oscillating magnetic field is varied to any frequency in a predetermined frequency range.

6. The system of claim 5, wherein the predetermined frequency range is between 1 kHz and 100 MHz.

7. The system of claim 1, wherein said resonators are coupled to adjustable electrical components.

8. The system of claim 7, wherein the resonant frequency of said resonators is varied by tuning at least one value of said adjustable electrical components.

9. The system of claim 7, wherein said magnetic resonators are high-Q magnetic resonators.

10. The system of claim 9, wherein the quality factor of said magnetic resonators is at least 100.

11. The system of claim 9, wherein the quality factor of said magnetic resonators is at least 100 for more than one frequency.

12. The system of claim 1, wherein the frequency of said oscillating magnetic field is changed to reduce interference with other power transfer systems.

13. A wireless energy transfer system comprising:

a source, having at least one source magnetic resonator, each resonator having a resonant frequency;

at least one power and control circuit, coupled to a power source, and configured to energize at least one source magnetic resonator to generate an oscillating magnetic field;

a device, having at least one device magnetic resonator configured to capture said oscillating magnetic field, each device magnetic resonator having a resonant frequency;

wherein magnetic energy transferred by the source to the device is converted into electrical energy by one or more device resonators;

wherein frequency of said oscillating magnetic field of said source is varied in time;

wherein said oscillating magnetic field generated by the source is substantially at the resonant frequency of the energized source magnetic resonator; and

wherein different said source magnetic resonators are energized depending on the frequency of said oscillating magnetic field.

14. The system of claim 13, wherein the frequency of said oscillating magnetic field is varied to prevent power transfer to unauthorized devices.

15. The system of claim 13, wherein the frequency of said oscillating magnetic field is varied in time to a random value within a predetermined frequency range.

16. The system of claim 13, wherein the frequency of said oscillating magnetic field is varied between a set of discrete frequencies.

17. The system of claim 13, wherein the frequency of said oscillating magnetic field is varied to any frequency in a predetermined frequency range.

18. The system of claim 17, wherein the predetermined frequency range is between 1 kHz and 100 MHz.

19. The system of claim 13, wherein said resonators are coupled to adjustable electrical components.

20. The system of claim 19, wherein the resonant frequency of said resonators is varied by tuning at least one value of said adjustable electrical components.

21. The system of claim 19, wherein said magnetic resonators are high-Q magnetic resonators.

22. The system of claim 21, wherein the quality factor of said magnetic resonators is at least 100.

23. The system of claim 21, wherein the quality factor of said magnetic resonators is at least 100 for more than one frequency.

24. The system of claim 13, wherein the frequency of said oscillating magnetic field is changed to reduce interference with other power transfer systems.

25. A wireless energy transfer system comprising:

a source, having at least one source magnetic resonator, each resonator having a resonant frequency;

at least one power and control circuit, coupled to a power source, and configured to energize at least one source magnetic resonator to generate an oscillating magnetic field;

a device, having at least one device magnetic resonator configured to capture said oscillating magnetic field, each device magnetic resonator having a resonant frequency;

wherein magnetic energy transferred by the source to the device is converted into electrical energy by one or more device resonators;

wherein frequency of said oscillating magnetic field of said source is varied in time;

wherein said oscillating magnetic field generated by the source is substantially at the resonant frequency of the energized source magnetic resonator; and

wherein the frequency of said oscillating magnetic field is changed to multiplex power to multiple device resonators tuned to different resonant frequencies.

26. The system of claim 25, wherein the frequency of said oscillating magnetic field is varied to prevent power transfer to unauthorized devices.

27. The system of claim 25, wherein the frequency of said oscillating magnetic field is varied in time to a random value within a predetermined frequency range.

28. The system of claim 25, wherein the frequency of said oscillating magnetic field is varied between a set of discrete frequencies.

29. The system of claim 25, wherein the frequency of said oscillating magnetic field is varied to any frequency in a predetermined frequency range.

30. The system of claim 29, wherein the predetermined frequency range is between 1 kHz and 100 MHz.

31. The system of claim 25, wherein said resonators are coupled to adjustable electrical components.

32. The system of claim 31, wherein the resonant frequency of said resonators is varied by tuning at least one value of said adjustable electrical components.

33. The system of claim 31, wherein said magnetic resonators are high-Q magnetic resonators.

34. The system of claim 33, wherein the quality factor of said magnetic resonators is at least 100.

35. The system of claim 33, wherein the quality factor of said magnetic resonators is at least 100 for more than one frequency.

36. The system of claim 25, wherein the frequency of said oscillating magnetic field is changed to reduce interference with other power transfer systems.

37. A wireless energy transfer source comprising:

at least one source magnetic resonator, each resonator having a resonant frequency;

at least one power and control circuit, coupled to a power source, and configured to energize at least one source magnetic resonator to generate an oscillating magnetic field;

wherein the frequency of said oscillating magnetic field of said source is varied in time in a predetermined sequence;

wherein said oscillating magnetic field generated is substantially at the resonant frequency of the energized source magnetic resonator; and

wherein the quality factor of said magnetic resonators is maintained above 100 as the source frequency is changed.

38. The source of claim 37, wherein the quality factor of said magnetic resonators is at least 100.

39. The source of claim 37, wherein the resonant frequency of the energized source magnetic resonator may be varied using at least one tunable electrical component.

40. A wireless energy transfer device comprising:

at least one device magnetic resonator, each resonator having a resonant frequency, is configured to capture an oscillating magnetic field with a frequency that is varied in a predetermined sequence;

at least one tunable electrical component coupled to at least one said magnetic resonator wherein the resonant frequency of at least one said magnetic resonator is varied in the same said predetermined sequence as the said oscillating magnetic field;

wherein magnetic energy transferred to the device via the said oscillating magnetic field is converted into electrical energy by the one or more device resonators;

wherein the quality factor of said magnetic resonators is maintained above 100 as device frequency is changed.

41. The source of claim 40, wherein the quality factor of said magnetic resonators is at least 100.

42. The source of claim 40, wherein the resonant frequency of the energized device magnetic resonator may be varied using at least one tunable electrical component.